Astrophysics

Title:
Holography and the scale-invariance of density fluctuations

Abstract: We study a scenario for the very early universe in which there is a fast
phase transition from a non-geometric, high temperature phase to a low
temperature, geometric phase described by a classical solution to the Einstein
equations. In spite of the absence of a classical metric, the thermodynamics of
the high temperature phase may be described by making use of the holographic
principle. The thermal spectrum of fluctuations in the high temperature phase
manifest themselves after the phase transition as a scale invariant spectrum of
fluctuations. A simple model of the phase transition confirms that the near
scale invariance of the fluctuations is natural; but the model also withstands
detailed comparison with the data.